Written by Miguel Leon Rios
The COVID-19 Vaccine Landscape
The global COVID-19 pandemic picture is still unclear as the novel coronavirus outbreak shifts constantly around the world. While the number of cases rise critically in South America’s first wave, the UK and European countries have begun to lift their lockdown measures amidst this COVID-19 pandemic. At the same time, South Korea and China, where coronavirus cases seemed to have disappeared, have seen a second wave of infections. However, a common question emerges among this COVID-19 rollercoaster: Will we have a vaccine soon?
A matter of time
Timing is crucial in vaccine research. More than five months have passed since the genetic sequence of SARS- CoV-2, the virus that causes COVID-19, which was published on 11th January 2020. This discovery sparked an unprecedented global research effort to develop a vaccine against this disease1, involving next-generation technology platforms and novel approaches with a hope to speed up this process. However, vaccine development involves a multi-stage process of research and testing, which typically takes more than ten years to be completed2 (Fig. 1). Therefore, we must remain cautious in light of a new vaccine.
What is the current picture?
A recent overview of the global landscape of COVID-19 vaccines by the World Health Organisation (WHO) included more than 140 vaccine candidates from different research groups and developers around the world3. From those, 129 candidate vaccines are under preclinical evaluation, which means a preliminary laboratory exploration but not yet in human trials. On the other hand, 13 candidate vaccines have entered the clinical evaluation stage, which is a three-phase process involving human subjects (Fig. 2).
OK, but can we speed up this process?
In terms of vaccine research time we are progressing at super-fast speed in this scenario. Just consider that the first set of COVID-19 cases, a new type of viral pneumonia, were reported to WHO on 4th January 2020 (Fig.3). Two months later, the first COVID-19 vaccine entered first-in-human trials within record breaking time on 16th March 2020. Scientists and international organizations around the world are still racing to produce and deliver a safe and effective vaccine within an 18-month period1-3.
So, do we have a vaccine yet?
From the array of advanced COVID-19 candidates under clinical development, only one promising study has started their phase 3 trial in Brazil4 (Fig. 4). This a non-replicative viral vector vaccine developed by the University of Oxford and the British-Swedish company AstraZeneca5. As we previously described, this candidate works as an inactive vaccine by using a different non-live virus to deliver coronavirus genes into our cells. In other terms, it can´t reproduce itself but it can still provoke an immune response.
Currently, this vaccine is also moving to Phase II/III in England and will hopefully deliver positive results by next year. A different approach has been employed by The Murdoch Children’s Research Institute in Australia. The experimental coronavirus vaccine, which is currently in phase 3 trial, utilises the Bacillus Calmette-Guerin vaccine6. The BCG vaccine is made from a weakened strain of tuberculosis bacteria and been widely used since the 1920s to fight TB7.
Researchers expect to observe partial protection against SARS-COV-2 as observed for other diseases7,8. Only data and results will decide if the remaining vaccine candidates could progress to phase 3 human trials and if this global effort could be translated into a successful vaccine by early 2021.
- Usher AD. COVID-19 vaccines for all?. Lancet. 2020;395(10240):1822-1823. doi:10.1016/S0140-6736(20)31354-4
- Thanh Le T, Andreadakis Z, Kumar A, et al. The COVID-19 vaccine development landscape. Nat Rev Drug Discov. 2020;19(5):305-306. doi:10.1038/d41573-020-00073-5
- Draft landscape of COVID-19 candidate vaccines. WHO. 2020; June 22. [cited 2020 Jun 23]. Retrieved from https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines
- Corum.J, Grady. D and Zimmer. C. 2020. Coronavirus Vaccine Tracker. The New York Times. Available from: https://www.nytimes.com/interactive/2020/science/coronavirus-vaccine-tracker.html
- Current Controlled Trials. ISRCTN89951424. A phase III study to investigate a vaccine against COVID-19, [cited 2020 Jun 23]. Available from: https://doi.org/10.1186/ISRCTN89951424
- ClinicalTrials.gov. NCT04327206, BCG Vaccination to Protect Healthcare Workers Against COVID-19 (BRACE) [cited 2020 Jun 23]. Available from: https://clinicaltrials.gov/ct2/show/NCT04327206
- World Health Organization. BCG vaccine: WHO position paper, February 2018 Recommendations. Vaccine. 2018;36(24):3408-3410. doi:10.1016/j.vaccine.2018.03.009
- Caryn Rabin R. 2020, April 5. Can an Old Vaccine Stop the New Coronavirus?. The New York Times. Available from: https://nyti.ms/2JCcTxx